The invention concerns a process for the mixing of gases, particularly for installations for the treatment of workpieces with the aid of plasma discharges, such as glow discharges, whereby the gases are introduced in corresponding amounts by way of metering valves into a mixing chamber, whenever the pressure in said mixing chamber drops below a predetermined value: the mixture of gases being passed from the mixing chamber to a consumer.
Gas mixing installations for small volumes of gas, such as those needed for the treatment of workpieces by means of glow discharge, may be readily constructed with the aid of the flow meters and needle valves or flow regulators. Herein, however, the accuracy and reproducibility of the mixing ratio that may be attained presents a problem: these values are low. In case of a varying rate of removal of the gas, the mixing ratio is not constant. Furthermore, any change in the mixture must be adjusted manually during the operational flow of the gas, in keeping with the indication of the flow meter.